Improvement in adjustable mandrels



UNITED STATES PATENT OFFICE.

CHARLES W. LE COUNT, OF NORWALK., CONECTICUT.

IMPROVEMENT IN ADJUSTABLE MANDRELS.

Specification forming part of Letters Patent No. 55,681, dated June 19, 1866.

.To all 'whom it lmay concer-a:

Be it known thatI, CHARLES W. LE COUNT, of the town of Norwalk, county ot' Fairfield, and State ot Connecticut, have invented new .and useful Improvements in the Mode of Constructing Adjustable Maudrels for the use of Lathes 5 and I do hereby declare that the following' is a correct description thereof, reference being had to the accompanyingdrawings, and to the letters of reference marked thereon.

The nature of my invention consists in the arrangement of a mandrel for lathes with adjustable sliding keys.

hole at each end for the lathe-centers in the nsnal manner.

ln the parallel part at A, I cut a screw with a fine thread to receive the socket B, which has an internal or female thread lo correspond with the thread on the mandrel A. On the forward end ofthesocket B, lcut an external thread of about double the pitch of the thread on the mandrel A. I then makeathimble, C, with aniuternal thread toscrew onto the external thread of the socket B. This thimble C has a square projection, G, at the forward end, internally, to catch on and press on a similar projection, H, ot' each ot' the sliding keys F to bring them back and cause them to slide in the inclined grooves E of the mandrel to enlarge their diameters at the level part where the article (marked D) or any other is put on to be operated on.

The forward part of the mandrel, Fig. l, say about halfway, is prepared to form the adjusting part of the same by being made tapering in the usual mechanical manner. In this taper part I form three or four grooves, E, on the periphery ofthe same of a suitable size and depth, and the sides a little dovetailing, to receive the adjusting keys F, which are made Vto fit in the grooves E and slide in the same.

At the hack end of the keys F (see Fig. 3) I make a square projection, G, to correspond and act with the projection in the interior of the thimhle C. These projections are the means that tighten the keys F to the object to be operated on by drawing them hack and up the inclined groove in the tapered part of' the mandrel by the combined movementof the socket B and thimble C.

The keys F are made parallel and are sunk down in strips, as shown in Fig. 3, to give that part a perfectly level horizontal space or bearing when placed in the grooves; and it is the sliding up the grooves that expands their diameter to fasten lirmly the article to be turned.

To operate my mandrel, tirst screw on the socket B; then place the keys Fin the grooves E; then place on the thimhle C, the keys being sut'liciently forward Vand loose; now put on the article, (see the piece marked D5) then screw the thimhle C onto the socket B, screw back both socket and thimble, and the projection in the thimble will draw back the keys F up the inclined grooves E, and the parallel level partsot' the keys will expand in diameter to firmly fasten the article I) for operation.

When required to take oft' the linished article, screw forward the combined socket B and thimble C, and the forward end of the socket B will press against the end projection, H, ofthe keys F and force them down the i11- clinedgrooves and loosen the whole, so that the article can be taken otf.

Flat spaces are made on the mandrel for the use of a wrench and a pin or other device for the dog ofthe lathe face-plate to carry round the same in the usual manner.

There are no limits to the sizeof this adjustable mandrel, and it is both useful and convenient.

What I claim as my invention, and desire to secure by Letters Patent, is-

The arrangement of the sliding keys F, socket B, and thimble C, in combination with the mandrel A, in the manner and for the purpose substantially as herein described.

C. XV. LE COUNT.

Witnesses:

WM. VINE, J. CHURCH, Jr. 

